You had 389 friends on Facebook yesterday but today that number the decreased to say 387. How do you find out the names of those two souls who have decided to unfriend you on Facebook?

Now Facebook won’t notify you when people remove you from their friends list but if you would still want to have that data, there’s a web app called Twenty Feet that can help reveal the names of your ex-friends.

The idea is simple. You connect your Facebook account with Twenty Feet and it makes a note of all the Facebook profiles that are listed as your Facebook friends. It fetches this data every day and alerts if it finds one or more connections that have gone missing from your Facebook friends list.

There are two possibilities – either the person has quit Facebook altogether or they have unfriended you for some reason. Other than Facebook, you may also use Twenty Feed to track your lost followers on Twitter (see alternatives).

Twenty Feet takes a freemium approach – you can track one Facebook account and one Twitter account for free – which I think should work for most of us but if you are business, the cost of tracking is still pretty affordable at $2.49 per account per year.

The following video will show you how you can use TwentyFeet to find out who has unfriended you on Facebook. Obviously, it can only track friends that have deserted you after you have joined the Twenty Feet service.

Amit Agarwal is a web geek and founder of Digital Inspiration, a popular tech & how-to website. He has been blogging for over a decade and has also contributed to the Wall Street Journal, Lifehacker and The Financial Express. Sign-up for the email newsletter for your daily dose of tips & tutorials.